feat(ui5-shellbar): replace custom badges with ButtonBadge

[NakataCode]

Changes to the Template:

• Removed data and notification attributes from buttons
• Added ButtonBadge component to handle:
  • Notification counts (notificationsCount)
  • Data counts (item.count)
  • Overflow notification counts (_overflowNotifications)

Changes to the CSS:

• Removed pseudo-element styles previously used for badges
• Added offset to bell button badge to prevent clipping
• Added offset to last button in overflow container to prevent badge clipping

Changes to the tests:

• Removed outdated tests that checked for data-count attributes
• Added three new Cypress tests covering ButtonBadge functionality:
  • Verification of count display
  • Validation of count updates
  • Testing of overflow badge behavior

[Copilot]

Copilot reviewed 4 out of 6 changed files in this pull request and generated 1 comment.

Files not reviewed (2)

• packages/fiori/src/themes/ShellBar.css: Language not supported
• packages/main/src/themes/base/rtl-parameters.css: Language not supported

Comments suppressed due to low confidence (1)

packages/fiori/src/ShellBar.ts:1133

• Replacing the isIconHidden() function with a direct class check may not cover all intended cases; please confirm that checking for 'ui5-shellbar-hidden-button' is sufficient for your use case.

if (item.count && item.classes.includes("ui5-shellbar-hidden-button")) {